It forms a break in the eastern Andes, separating the Tamá Massif to the west from the Cordillera de Mérida to the east.

The depression has been thought to present a barrier to the movement of species between the Colombian and Venezuelan Andes, but this effect may have been relatively low during the recent ice ages.

[2] This gap between the Colombian and Venezuelan Andes is a product of orogenic movements in the Paleogene period that created major faults, raised blocks and formed rifts including the Táchira Depression.

[1] There are four faults with northwest-southeast trends aligned in echelon across the Tachira depression between Córdoba in Colombia to the west and Torondoy in Venezuela to the east.

The climate is tropical in the premontane piedmont and the low mountains, and in some valleys, semi-arid in regions like Lobatera, San Antonio del Táchira and Ureña, and humid in the upper and middle basins of the Uribante, Dorados and Camburito rivers.

On the southeastern slope the influence of air masses from the llanos causes a single rainy season, usually from April to November.

In some areas the lack of water means that agriculture depends on irrigation, while in others the excess rain causes erosion and flooding.

[7] However, during the Last Glacial Maximum from around 26,500 to 20,000 years before the present the cooler climate led to upper vegetation belts moving down to lower regions.

[10] Coal mining in the Táchira depression may threaten the Venezuelan Andes montane forests ecoregion in the adjacent Tamá Masif.